Traversing film cutter

ABSTRACT

The apparatus includes a motor; a guide rod; a blade mounted for reciprocable movement on the guide rod in response to the actuation of the motor; and an actuating bar over which film is pulled and which energizes the motor in response to the pressure applied to it by the stretched film, the blade is returned to its starting position when the pressure on the actuating bar is removed and the rotation of the motor is thus reversed.

United States Patent 1191 Feinstein et al.

1451 July 31,1973

[ TRAVERSING FILM CUTTER [75] Inventors: Sumner Sheldon Feinstein, WestPeabody; Jerold Julius Golner, Lowell; Anthony Salvatore D'Amato,Chelmsford; Eugene John Trunk, North Andover, all of Mass.

[73] Assignee: Borden, Inc., Columbus, Ohio [22] Filed: Aug. 11, 1971[21] Appl. No.: 170,707

[52] US. Cl 83/370, 53/390, 83/524, 83/614 [51] Int. Cl 826d 5/08 [58]Field of Search 83/370, 372, 614, 83/524, 484; 53/390 [56] ReferencesCited UNITED STATES PATENTS 3,540,337 11/1970 Gardner 83/614 X 3,082,923Ford et al. 83/370 x 2,670,040 2/1954 SayleS 83/484 3,633,447 1/1972Casida 83/484 3,641,854 2/1972 Keesling. 83/614 x 3,146,661 9/1964 Young83/614 x FOREIGN PATENTS OR APPLICATIONS 785,372 10/1957 Great Britain53/390 Primary ExaminerJ. M. Meister Attorney-George P. Maskas et al.

[5 7 ABSTRACT The apparatus includes a motor; a guide rod; 21 blademounted for reciprocable movement on the guide rod in response to theactuation of the motor; and an actuating bar over which film is pulledand which energizes the motor in response to the pressure applied to itby the stretched film, the blade is returned to its starting positionwhen the pressure on the actuating bar is removed and the rotation ofthe motor is thus reversed.

16 Claims, 8 Drawing Figures PAIENIED 1 1975 3. 748.939

saw 1 or 3 PATENTEUJUL31 191a SHEEI 2 (IF 3 PAIENIED J 1 SHEET 3 0F 3 ITRAVERSING FILM CUTTER This invention relates in general to a device forfacilitating the cutting and dispensing of strip material and, inparticular, to a new and useful cutting device adapted specifically forcutting thin plastic film, such as polyvinyl chloride. The devicecomprises a knife member driven across a feed path for the film by adriving motor which is actuated by a bar when the bar is depressed bythe film. When the film is cut, pressure on the bar is relieved therebyactuating the motor to return the knife member to its starting position.

The present invention is an improvement over the known devices forsevering strip material or film, principally with respect to theprovision of means for automatically returning the cutting blade to itsinitial position, and also in the arrangement which permits the simpleoperation of the cutting mechanism after the film is stretched over atray for goods to be covered thereby. With the inventive device, it is asimple matter to grasp the end of a length of strip material and pull itoff its supply roll as the outer end is wrapped around the tray and tothereafter move the strip material over the top of the tray and tolocate the trailing portion of the film in a position over a guidechannel along which a cutting knife is movable. An important feature ofthe invention is the provision of an actuating bar which is designed tobe depressed easily by either the tray being covered or by the stretchedstrip of plastic material which engages over the top thereof, as theoperator pulls the material away from its supply roll. The actuating barcauses a driving motor to move a cutting knife across to sever the stripmaterial in response to being depressed and as soon as the stripmaterial is severed, the actuating bar is released and this causes themotor to return the cutting knife to its original position. On itsreturn, the knife actuates a micro switch which deenergizes the motor inorder to reduce the impact of the knife when it slams into the abutment.

This is a mechanical cutting device which affects physical severing bymeans of a sharp blade maintained at ambient temperature. Since theinternal elements are substantially enclosed within the housing, thereis no danger of scraps of meat, or anything else that is being packaged,falling into the device thus requiring its removal. Another practicaladvantage of the present invention relates to the construction of thecutting device which can be easily disassembled for cleaning,examination or for replacement of parts. To remove the actuating bar,all that is required is to manually ease the pins of the actuating barout of the recesses provided in the end blocks. As for the cover plate,all that is needed to remove it is the extraction of four screws with ascrewdriver. The fact that the device is constructed of stainless steel,or other metal acceptable for food processing, also facilitates cleaningand general maintenance thereof.

Accordingly, it is an object of this invention to provide an improveddevice for facilitating the covering of small trays which includes ablade member actuatable by the stretching of a plastic film over a guidebar as the tray is being covered and means for immediately returning theknife to its starting position after the plastic film has been severed.It is another object to provide a simple means, particularly forapplying thin polyvinyl chloride plastic film for covering disposabletray packages for food products, such as meats, with which means it is asimple matter to orient one end of the plastic film over one end of thepackage and to direct the remaining portion across the top to cover theproduct in the tray and then to position the trailing part over theactuating bar at a spaced location from the tray alongside the cuttingblade whereby stretching of the film across the actuating bar depressesthe bar and energizes the motor to drive the knife across and sever thefilm.

Accordingly, it is another object of the invention to provide animproved device for cutting strip material, particularly plastic film,which includes a movable knife driven across a feed path of the film inresponse to the depression of the actuating bar located adjacent thepath and means for returning the knife to its starting position. Afurther object of the invention is to provide a device for facilitatingthe dispensing and cutting of sheet or strip material, particularly thinplastic film or foil, which includes means for guiding a length of thesheet material over a guide bar to permit the end thereof to bewithdrawn and engaged over a tray to be covered, and an actuating baralongside the guide bar which is depressed by tensioning the sheet tocause the blade member to move across the guide bar and cut the sheetmaterial. A further object of the invention is to provide a device fordispensing and cutting thin plastic film which is simple in design,rugged in construction, economical to manufacture, simple to clean andwhich is adaptable to quick replacement of parts.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference should be had to the accompanying drawings and descriptivematter in which there is illustrated a preferred embodiment of theinvention.

FIG. 1 is a front perspective view of the device for cutting thin sheetsof various materials, especially plastic film, which may be used tocover food products disposed in trays;

FIG. 2 is a front planar view of the cutting device with the actuatingbar and the cover plate removed;

FIG. 3 is a view of the cuttingdevice taken along plane 3-3 in FIG. 2;

FIG. 4 is a side view of the film cutting device illustrating therelationship of the actuating bar to the yieldable means which serves tomove the actuating bar away from the micro switch and the cover plate;

FIG. 5 is a perspective view of one of the endblocks;

FIG. 6 is a perspective view of the actuating bar provided with a-pin ateach end which are inserted into the cooperating recesses in the endblocks;

FIG. 7 is a perspective view of the blade carriageprovided with a blade;and

FIG. 8 is a general diagram of the electrical circuit which activatesthe cutting device.

Referring to the drawings in particular, the invention embodied thereincomprises a device for facilitating the covering of small disposablefood trays 10 which are of an inexpensive material such as pressed orfoamed plastic, fiberboard and the like. The trays are adapted tocontain a food product such as meat 12 which is covered with thinplastic film or foil material 14. This material is preferably a clingingtype plastic film such as polyvinyl chloride.

The apparatus includes a mounting stand generally designated 16 whichprovides a mounting for a reel supply (not shown) of the plastic film 14which is fed outwardly in a horizontal path indicated by the arrow 18between guide rollers 20,22.

When tray is to be wrapped or covered with a plastic film, outermarginal edges of film 14 are grasped by hands 26, indicated in dottedlines, and guided about the tray disposed on ramp 24 so that the tray isenveloped by the film. A sheet of film is then severed and the free endis brought under the tray and sealed by means of heat supplied to ramp24.

In accordance with this invention, there is provided an automaticallyoperable cutting mechanism located directly adjacent to ramp 24 whichincludes an actuating bar 28 and reciprocable blade carriage 30 mountedin housing 32. As shown in FIG. 6, actuating bar 28 has an elongatedform and is provided with a pair of mounting ears 34 at its ends and aflange 36 at its bottom which extends away from the operator. In orderto maintain the actuating bar away from a micro switch when the cuttingdevice is in an inoperable condition, as will be fully described, anabutment 37 is affixed at the right lowermost portion of the actuatingbar. Abutment 37 contacts a spring or a yieldable bumper and thusmaintains the actuating bar spaced away from the micro switch, unless aforce is applied to the actuating bar, in which case, the micro switchis actuated and the blade carriage is automatically reciprocated. Outerportions of the mounting cars 34 have affixed thereto inwardly directedpins 38, 40 which support and maintain the actuating bar in operablerelationship with the cutting device, as will be described.

As is apparent from FIGS. 3 and 4, housing 32 includes cover plate 42,base plate 44 provided with flange 45, and end blocks 46,48 disposed onthe base plate at its opposite ends and secured thereto by suitablemeans, such as screws. The cover plate 42 is L- shaped and has adepending flange 50 with one leg of cover plate 42 resting on flange 45.The base plate is also L-shaped and combines with the cover plate 42 toform an elongated box-like structure. The cover plate is affixed to thebase plate and the end blocks by four screws, which can be easilyremoved.

FIG. 7 shows that blade carriage 30 is a U-shaped member having a pairof spaced legs 54,56 and a depending supporting lug 58 having an openrecess 59. As is evident from FIG. 3, blade carriage 30 is slidablymounted on rod 60 which is supported by the end blocks 46,48 and extendsfrom one end to the other of the cutting device. The blade carriagereciprocates on rod 60 between snubbers 62,64, shown in FIG. 2, whichabsorb the impact force when the blade carriage is rammed thereagainst.The snubbers are cylindrical and are slipped over the ends of the rod.Material for the snubbers is selected so that it is sufficientlyresilient to absorb the force of impact. Suitable materials are plasticsand rubbers.

FIG. 7 shows blade carriage 30 provided with blade 51, which can be anordinary Schick injector blade. Blade 51 is disposed in slot 53 of theblade holder and is maintained in a position by a removable plate 55. Inorder to prevent cuts to the hands of the operator, the blade holder hasa protruding guard 57 which prevents fingers from coming into contactwith the blade.

Also mounted within the housing are a pair of spaced pulleys 66,68,which are affixed to the base plate.

These pulleys are positioned at ends of the base plate and haveentrained thereabout cord 70. As is best shown in FIG. 3, the bladecarriage is affixed to cord by means of a frictional engagement betweenopen recess 59 in the blade carriage and the cord. This arrangement isvery practical when it is desired to replace the cord in that the bladecarriage can be easily detached from the cord by pulling the cord out ofrecess 59.

Yieldable means which maintains the actuating bar spaced away from themicro switch, and therefore, in an inactivate position, is a spring or ayieldable bumper 61 positioned at the right extremity of the cuttingdevice in end block 48. Resilient bumper 61 cooperates with abutment 37to position the actuating bar in spaced relationship to the microswitch.

The motive force to rotate one of the pulleys is supplied by motor 72affixed to the rear of base plate 44. A suitable motor for this purposeis the Triem, Inc., l/SOHP, split-capacitor motor. Automatic operationof the cutting device is controlled by main micro switch 74 disposed atthe left on base plate 44 and an auxiliary micro switch 75 locatedtowards the right end and also affixed to base plate 44. Micro switch 75includes deflector lever 76 and actuating button 78.

A simplified diagram of the circuit and the micro switches isillustrated in FIG. 8. Switch 74 has a normally open (NO) and normallyclosed (NC) circuits. The NO circuit, when actuated, moves the bladeholder from right to left while the NC circuit, returns it to itsstarting position. Switch 74 is normally open and is actuated when theactuating bar contacts actuating button 80. When the main switch 74 isactuated, the NO circuit is closed and the motor is energized to movethe blade carriage from right to left, as seen in FIG. 2. Snubber 62absorbs the impact when contact with the blade holder is made, andbrings it to rest. In this position, the normally closed (NC) circuit isinactive. When film is cut, pressure on the actuating bar is releasedand resilient bumper 61 displaces the actuating bar to its normalposition away from button of main micro switch 74 and actuates the NCcircuit by sending a signal to the motor through the auxiliary microswitch 75, which is in NC position. The motor is energized in thereverse direction and returns the blade carriage to its startingposition. On its return, blade carriage depresses button 78 of microswitch 75 by deflecting lever 76 to open the return circuit and thusde-energize the motor. Although the motor is tie-energized when theblade holder traverses micro switch 75, the generated momentum slams theblade holder against snubber 64 which absorbs the shock and brings theblade holder to rest. In order to reduce the impact, deflecting lever 76is purposely elongated and made of stiff metal to provide somerestraining force. The time that it takes to move the blade holder fromright to left and then back to its initial position is about 0.04seconds.

In another embodiment of the apparatus described herein, retraction ofthe blade carriage is accomplished by means of a spring. This can bedone in several ways, one of which involves a coil spring wound on apulley with the free end thereof attached to the blade carriage. Themotor is a one-way motor which is deactivated upon moving the bladecarriage from its initial position across the feed path for the plasticfilm, to allow the spring to return the blade carriage to its startingposition.

What is claimed is:

1. Apparatus for severing sheet material comprising an elongated cutterguide means over which the sheet material is directed in the transversedirection, a cutting means associated with said cutter guide means andmovable therealong across the sheet material, a drive means connectedwith said cutting means for moving same along said cutter guide means tosever the sheet material, and a yieldably mounted elongated actuatingmember disposed parallel to the travel of said cutting means and aheadof said cutting means for energizing said drive means in response topressure applied by the sheet material when it is pulled over saidactuating member, the sheet material first passing over said cutterguide means and then over said actuating member.

2. Apparatus of claim 1, wherein said elongated member is disposedparallel to and spaced from said cutter guide means to allow saidcutting means to move between said elongated member and said cutterguide means, said apparatus including a main switch which is in anormally open condition, said drive means being energized by said mainswitch which in turn is actuated by said elongated member to move saidcutting means across the feed path of the sheet material and back to itsstarting position in response to de-actuation by said elongated member.

3. Apparatus. of claim 2 which includes yieldable means for maintainingsaid actuating means in spaced relationship to said main switch, a pairof spaced pulleys and a cord stretched between said pulleys, said drivemeans is coupled to one of said pulleys and said cutting means isaffixed to said cord and moves therewith in response to the rotation ofsaid pulleys and movement of said cord.

4. Apparatus of claim 3 wherein said cutting means includes a bladecarriage which is frictionally affixed to said cord and a bladeremovably secured to said blade carriage.

5. Apparatus of claim 4 includingsnubbers provided at both ends of saidcutter guide means for absorbing the impact force of said blade carriageand an auxiliary switch disposed ahead of said blade carriage when saidblade carriage is in its starting position, said auxiliary switch beingprovided for de-energizing said drive means when said blade carriage isreturned to its starting position.

6. Apparatus of claim 5 wherein said blade carriage includes aprojecting guard disposed over said blade which protects hands of anoperator from said blade, said blade carriage also includes a plate forremovably securing said blade to said blade carriage.

7. Apparatus of claim 6 which includes a housing within which aredisposed said cutter guide means, said pulleys, said main and auxiliaryswitches and said snubbers, said drive means being affixed on theexterior of said housing.

8. Apparatus of claim 7 wherein said blade carriage comprises a pair ofspaced parallel legs joined together at the bottom and generallycorresponds to a letter U, one leg supports said blade while the other adepending lug, said depending lug has an opening which slidablyaccommodates said cutter guide means and a recess which serves tofrictionally engage said cord.

9. Apparatus of claim 8 wherein said housing comprises four wallsdisposed at right angles to each other and a slot, which permits one legof said blade carriage to enter interior of said housing, at least aportion of one of said walls being disposed between the two legs of theU-shaped blade carriage, said leg supporting said lug being disposedwithin said housing while said leg supporting said blade being disposedbetween said housing and said actuating means. v

10. Apparatus of claim 9 which includes end blocks disposed within theopposite ends of said housing, each of said end blocks includes arecess; said cutter guide means is an elongated rod which is supportedat both ends by said end blocks; and said elongated member includes alateral extension at each side thereof provided with inwardly directedpins which removably fit within the recesses in said end blocks.

1 1. Apparatus of claim 10 wherein said housing comprises a top and abottom mating L-shaped plate section, said top section being removablysecured to said bottom section and said end blocks, said sheet materialis a plastic film wound on a roll.

12. Apparatus of claim 11 wherein said drive means is a capacitor motor,said main switch is a three lead micro switch which is normally in theopen condition, and said auxiliary switch is a micro switch including aresilient lever which is depressed by said blade carriage on its returnto thus actuate said auxiliary switch to deenergize said drive means,said resilient lever being of sufficient stiffness to slow down saidblade carriage on its return to its starting position.

13. Apparatus of claim 2 wherein said drive means is a 1/50 HP capacitormotor.

14. Apparatus for severing sheet material comprising a housing disposedtransversely to the feed path of the sheet material having a pair of endwalls; a pair of pulleys affixed at opposite ends within said housing;an endless cord entrained over said pulleys; drive means coupled to oneof said pulleys; a normally open threelead micro switch mounted withinsaid housing but partially extending outside thereof for actuating saiddrive means; a guide bar disposed in said housing and supported by saidend walls; snubbers mounted on ends of said guide bar to absorb impactforce of a blade carriage; a blade carriage slidably mounted on saidguide bar comprising a pair of spaced legs joined at the bottom, one legof said blade carriage extends into said housing and has a lug providedwith an opening slidably accomodating said guide bar and a recess withinwhich is frictionally engaged said endless cord, while the other leg isdisposed outside of said housing and is provided with a blade; anauxiliary micro switch mounted within said housing adjacent said bladecarriage when the latter is in its starting position to de-energize saiddrive means when said blade carriage acutates said auxiliary microswitch on its return to the starting position; an actuating barremovably mounted on said housing and being spaced from said housing topermit said blade to travel between said housing and said actuating barto sever the sheet material fed over said housing and said actuatingbar, said actuating bar being actuated by stretching the sheet materialthereover; yieldable means for maintaining said actuating bar in spacedrelationship to said housing and said three-lead micro switch, saiddrive means is energized to move said blade carriage from one end of theapparatus to the other by displacing said actuating bar into contactwith said three-lead switch, the blade carriage is returned to itsstarting position by permitting said actuating bar to be displaced toits original position when the sheet material is severed.

a three-lead micro switch which is in a normally open condition and isactuated by depression of said actuating member to move said cuttingmeans across said sheet material and back to its starting position, saidapparatus including an auxiliary micro switch to deenergize said drivemeans when said cutting means actuates it on its return to the startingposition.

a: s: u: 4: s

1. Apparatus for severing sheet material comprising an elongated cutterguide means over which the sheet material is directed in the transversedirection, a cutting means associated with said cutter guide means andmovable therealong across the sheet material, a drive means connectedwith said cutting means for moving same along said cutter guide means tosever the sheet material, and a yieldably mounted elongated actuatingmember disposed parallel to the travel of said cutting means and aheadof said cutting means for energizing said drive means in response topressure applied by the sheet material when it is pulled over saidactuating member, the sheet material first passing over said cutterguide means and then over said actuating member.
 2. Apparatus of claim1, wherein said elongated member is disposed parallel to and spaced fromsaid cutter guide means to allow said cutting means to move between saidelongated member and said cutter guide means, said apparatus including amain switch which is in a normally open condition, said drive meansbeing energized by said main switch which in turn is actuated by saidelongated member to move said cutting means across the feed path of thesheet material and back to its starting position in response tode-actuation by said elongated member.
 3. Apparatus of claim 2 whichincludes yieldable means for maintaining said actuating means in spacedrelationship to said main switch, a pair of spaced pulleys and a cordstretched between said pulleys, said drive means is coupled to one ofsaid pulleys and said cutting means is affixed to said cord and movestherewith in response to the rotation of said pulleys and movement ofsaid cord.
 4. Apparatus of claim 3 wherein said cutting means includes ablade carriage which is frictionally affixed to said cord and a bladeremovably secured to said blade carriage.
 5. Apparatus of claim 4including snubbers provided at both ends of said cutter guide means forabsorbing the impact force of said blade carriage and an auxiliaryswitch disposed ahead of said blade carriage when said blade carriage isin its starting position, said auxiliary switch being provided forde-energizing said drive means when said blade carriage is returned toits starting position.
 6. Apparatus of claim 5 wherein said bladecarriage includes a projecting guard disposed over said blade whichprotects hands of an operator from said blade, said blade carriage alsoincludes a plate for removably securing said blade to said bladecarriage.
 7. Apparatus of claim 6 which includes a housing within whichare disposed said cutter guide means, said pulleys, said main andauxiliary switches and said snubbers, said drive means being affixed onthe exterior of said housing.
 8. Apparatus of claim 7 wherein said bladecarriage comprises a pair of spaced parallel legs joined together at thebottom and generally corresponds to a letter U, one leg supports saidblade while the other a depending lug, said depending lug has an openingwhich slidably accommodates said cutter guide means and a recess whichserves to frictionally engage said cord.
 9. Apparatus of claim 8 whereinsaid housing comprises four walls disposed at right angles to each otherand a slot, which permits one leg of said blade carriage to enterinterior of said housing, at least a portion of one of said walls beingdisposed between the two legs of the U-shaped blade carriage, said legsupporting said lug being disposed within said housing while said legsupporting said blade being disposed between said housing and saidactuating means.
 10. Apparatus of claim 9 which includes end blocksdisposed within the opposite ends of said housing, each of said endblocks includes a recess; said cutter guide means is an elongated rodwhich is supported at both ends by said end blocks; and said elongatedmember includes a lateral extension at each side thereof provided withinwardly directed pins which removably fit within the recesses in saidend blocks.
 11. Apparatus of claim 10 wherein said housing comprises atop and a bottom mating L-shaped plate section, said top section beingremovably secured to said bottom section and said end blocks, said sheetmaterial is a plastic film wound on a roll.
 12. Apparatus of claim 11wherein said drive means is a capacitor motor, said main switch is athree lead micro switch which is normally in the open condition, andsaid auxiliary switch is a micro switch including a resilient leverwhich is depressed by said blade carriage on its return to thus actuatesaid auxiliary switch to de-energize said drive means, said resilientlever being of sufficient stiffness to slow down said blade carriage onits return to its starting position.
 13. Apparatus of claim 2 whereinsaiD drive means is a 1/50 HP capacitor motor.
 14. Apparatus forsevering sheet material comprising a housing disposed transversely tothe feed path of the sheet material having a pair of end walls; a pairof pulleys affixed at opposite ends within said housing; an endless cordentrained over said pulleys; drive means coupled to one of said pulleys;a normally open three-lead micro switch mounted within said housing butpartially extending outside thereof for actuating said drive means; aguide bar disposed in said housing and supported by said end walls;snubbers mounted on ends of said guide bar to absorb impact force of ablade carriage; a blade carriage slidably mounted on said guide barcomprising a pair of spaced legs joined at the bottom, one leg of saidblade carriage extends into said housing and has a lug provided with anopening slidably accomodating said guide bar and a recess within whichis frictionally engaged said endless cord, while the other leg isdisposed outside of said housing and is provided with a blade; anauxiliary micro switch mounted within said housing adjacent said bladecarriage when the latter is in its starting position to de-energize saiddrive means when said blade carriage acutates said auxiliary microswitch on its return to the starting position; an actuating barremovably mounted on said housing and being spaced from said housing topermit said blade to travel between said housing and said actuating barto sever the sheet material fed over said housing and said actuatingbar, said actuating bar being actuated by stretching the sheet materialthereover; yieldable means for maintaining said actuating bar in spacedrelationship to said housing and said three-lead micro switch, saiddrive means is energized to move said blade carriage from one end of theapparatus to the other by displacing said actuating bar into contactwith said three-lead switch, the blade carriage is returned to itsstarting position by permitting said actuating bar to be displaced toits original position when the sheet material is severed.
 15. Apparatusof claim 14 wherein said three-lead micro switch includes a normallyopen and normally closed circuits, said blade carriage is returned toits original position when said actuating bar is relieved of pressurewhich has the effect of de-energizing the normally open circuit and ofenergizing the normally closed circuit to drive said blade carriage toits starting position.
 16. Apparatus of claim 2 wherein said main switchis a three-lead micro switch which is in a normally open condition andis actuated by depression of said actuating member to move said cuttingmeans across said sheet material and back to its starting position, saidapparatus including an auxiliary micro switch to de-energize said drivemeans when said cutting means actuates it on its return to the startingposition.